Neurogenesis in the adult brain comprises the entire set of events of neuronal development. It begins with the division of precursor cells to form a mature, integrated, and functioning neuronal ...network. Adult neurogenesis is believed to play an important role in animals’ cognitive abilities, including learning and memory. In the present study, significant neuronal differentiation-promoting activity of 80% (v/v) ethanol extract of P. cocos (EEPC) was found in Neuro-2a cells and mouse cortical neural stem/progenitor cells (NSPCs). Subsequently, a total of 97 compounds in EEPC were identified by UHPLC-Q-Exactive-MS/MS. Among them, four major compounds—Adenosine; Choline; Ethyl palmitoleate; and L-(-)-arabinitol—were further studied for their neuronal differentiation-promoting activity. Of which, choline has the most significant neuronal differentiation-promoting activity, indicating that choline, as the main bioactive compound in P. cocos, may have a positive effect on learning and memory functions. Compared with similar research literature, this is the first time that the neuronal differentiation-promoting effects of P. cocos extract have been studied.
Poria cocos is a widely used ingredient in traditional Chinese medicine and dietary supplement. In this study, the effects of the ethanol extract of P. cocos on cell proliferation in Neuro-2a ...neuroblastoma cells and its possible mechanism of action are investigated. The extract inhibited the growth of Neuro-2a cells in a dose-dependent manner with an IC50 value of 34.6 μg/mL. To further elucidate the mechanism by which the extract acts, transcriptome analysis using high-throughput Illumina RNA-seq technology was performed. Transcriptome analysis revealed that the cell cycle as the potential primary target pathway of the extract in Neuro-2a cells. Flow cytometry analysis confirmed that the extract induced cell cycle arrest at G1 phase. Furthermore, the extract also induced apoptosis in Neuro-2a cells. Notably, it was found that Neuro-2a cells exhibited morphological features of differentiation when treated with the extract. This study suggests that P. cocos may be a potential candidate therapeutic agent in combating neuroblastoma.
Crohn’s disease (CD) is well characterized by chronic inflammation of the gastrointestinal tract. The diagnose of CD relays on the comprehensive evaluation of patient symptoms, laboratory ...examination, radiology, and endoscopy. There is lack of biomarkers or simple test for CD detection. Serum samples from healthy subjects (
n
= 16) and CD patients (
n
= 16) were collected and prepared for untargeted metabolomics analysis using the ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS) method. The alterations of serum metabolites and the potential biomarkers were profiled by statistical analysis. And the associated metabolic pathway was analyzed based on Kyoto Encyclopedia of Genes and Genomes (KEGG) database. The performance of potential biomarkers was assessed by receiver operating characteristic (ROC) analysis. A complete separation between HS and CD groups was seen in OPLS-DA. A total of 108 and 131 significantly altered metabolites in positive and negative ion mode, respectively, were identified, and most of them belong to several pathways ranging from lipid metabolism to amino acid metabolism and energy homeostasis. KEGG analysis revealed that lipid metabolism enriched most significantly. Further, ceramide, phosphatidylethanolamine (PE), and taurochenodeoxycholic acid (TCDCA) presented the highest predictive accuracy of the patients with CD as analyzed by ROC. The current study demonstrated that lipid metabolism is mostly related to CD pathogenesis. Further investigations are indicated to examine the use of lipid-related metabolites of ceramide, PE, and TCDCA as potential biomarkers for CD diagnosis.
Extremely high or low autophagy levels disrupt plant survival under nutrient starvation. Recently, autophagy has been reported to display rhythms in animals. However, the mechanism of circadian ...regulation of autophagy is still unclear. Here, we observed that autophagy has a robust rhythm and that various autophagy‐related genes (ATGs) are rhythmically expressed in Arabidopsis. Chromatin immunoprecipitation (ChIP) and dual‐luciferase (LUC) analyses showed that the core oscillator gene TIMING OF CAB EXPRESSION 1 (TOC1) directly binds to the promoters of ATG (ATG1a, ATG2, and ATG8d) and negatively regulates autophagy activities under nutritional stress. Furthermore, autophagy defects might affect endogenous rhythms by reducing the rhythm amplitude of TOC1 and shortening the rhythm period of CIRCADIAN CLOCK‐ASSOCIATED 1 (CCA1). Autophagy is essential for the circadian clock pattern in seedling development and plant sensitivity to nutritional deficiencies. Taken together, our studies reveal a plant strategy in which the TOC1‐ATG axis involved in autophagy‐rhythm crosstalk to fine‐tune the intensity of autophagy.
The core circadian clock protein TIMING OF CAB EXPRESSION 1 directly regulates autophagy‐related genes, revealing that the circadian clock regulates the balance of cellular energy metabolism through autophagy and ultimately determines the fate of cells.
(
) has been recently identified as a new species of spider in China. It lives in the same habitat as various other venomous spiders, including
(
),
(
), and
(
). The venom from these different ...species of spiders exhibits some similarities and some differences in terms of their biochemical and electrophysiological properties. With the objective to illustrate the diversity in venom peptide toxins and to establish the evolutionary relationship between different spider species, we first performed transcriptomic analysis on a cDNA library from the venom gland of
. We identified 146 novel toxin-like sequences, which were classified into eighteen different superfamilies. This transcriptome was then compared with that of
, which revealed that the putative toxins from both spider venoms may have originated from the same ancestor, although novel toxins evolved independently in the two species. A BLAST search and pharmacological analysis revealed that the two venoms have similar sodium channel modulation activity. This study provides insights into the venom of two closely related species of spider, which will prove useful towards understanding the structure and function of their toxins.
Dolomedes sulfurous and Dolomedes mizhoanus are predaceous arthropods catching and feeding on small fish. They live in the same area and have similar habits. Their venoms exhibit some similarities ...and differences in biochemical and electrophysiological properties. In the present work, we first performed a transcriptomic analysis by constructing the venom gland cDNA library of D. sulfurous and 127 novel putative toxin sequences were consequently identified, which were classified into eight families. This venom gland transcriptome was then compared with that of D. mizhoanus, which revealed that the putative toxins from both spider venoms might have originated from the same gene ancestors although novel toxins were evolved independently in the two spiders. The putative toxins from both spiders contain 6-12 cysteine residues forming seven cysteine patterns. As revealed by blast search, the two venoms are rich in neurotoxins targeting ion channels with pharmacological and therapeutic significance. This study provides insight into the venoms of two closely related species of spider, which will be of use for future investigations into the structure and function of their toxins.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
ABSTRACT
Voltage‐gated sodium channels (NaVs) are activated by transiting the voltage sensor from the deactivated to the activated state. The crystal structures of several bacterial NaVs have ...captured the voltage sensor module (VSM) in an activated state, but structure of the deactivated voltage sensor remains elusive. In this study, we sought to identify peptide toxins stabilizing the deactivated VSM of bacterial NaVs. We screened fractions from several venoms and characterized a cystine knot toxin called JZTx‐27 from the venom of tarantula Chilobrachys jingzhao as a high‐affinity antagonist of the prokaryotic NaVs NsVBa (nonselective voltage‐gated Bacillus alcalophilus) and NaChBac (bacterial sodium channel from Bacillus halodurans) (IC50 = 112 nM and 30 nM, respectively). JZTx‐27 was more efficacious at weaker depolarizing voltages and significantly slowed the activation but accelerated the deactivation of NsVBa, whereas the local anesthetic drug lidocaine was shown to antagonize NsVBa without affecting channel gating. Mutation analysis confirmed that JZTx‐27 bound to S3–4 linker of NsVBa, with F98 being the critical residue in determining toxin affinity. All electrophysiological data and in silico analysis suggested that JZTx‐27 trapped VSM of NsVBa in one of the deactivated states. In mammalian NaVs, JZTx‐27 preferably inhibited the inactivation of NaV1.5 by targeting the fourth transmembrane domain. To our knowledge, this is the first report of peptide antagonist for prokaryotic NaVs. More important, we proposed that JZTx‐27 stabilized the NsVBa VSM in the deactivated state and may be used as a probe to determine the structure of the deactivated VSM of NaVs.—Tang, C., Zhou, X., Nguyen, P. T., Zhang, Y., Hu, Z., Zhang, C., Yarov‐Yarovoy, V., DeCaen, P. G., Liang, S., Liu, Z. A novel tarantula toxin stabilizes the deactivated voltage sensor of bacterial sodium channel. FASEB J. 31, 3167–3178 (2017). www.fasebj.org
Venomous toxins hold immense value as tools in elucidating the intricate structure and underlying mechanisms of ion channels. In this article, we identified of two novel toxins, Hainantoxin-XXI ...(HNTX-XXI) and Hainantoxin-XXII (HNTX-XXII), derived from the venom of the Chinese spider Ornithoctonus hainana. HNTX-XXI, boasting a molecular weight of 6869.095 Da, comprises 64 amino acid residues and contains 8 cysteines. Meanwhile, HNTX-XXII, with a molecular weight of 8623.732 Da, comprises 77 amino acid residues and contains 12 cysteines. Remarkably, we discovered that both HNTX-XXI and HNTX-XXII possess the ability to activate TRPV1. They activated TRPV1 with EC50 values of 3.6 ± 0.19 μM and 862 ± 56 nM, respectively. Furthermore, the current generated by the activation of TRPV1 by these toxins can be rapidly blocked by ruthenium red. Intriguingly, our analysis revealed that the interaction between HNTX-XXI and TRPV1 is mediated by three key amino acid residues: L465, V469, and D471. Similarly, the interaction between HNTX-XXII and TRPV1 is facilitated by four key amino acid residues: A657, F659, E600, and R601. These findings provide profound insights into the molecular basis of toxin-TRPV1 interactions and pave the way for future research exploring the therapeutic potential of these toxic peptides.
Selenocosmia jiafu is a medium-sized theraphosid spider and an attractive source of venom, because it can be bred in captivity and it produces large amounts of venom. We performed reversed-phase ...high-performance liquid chromatography (RP-HPLC) and matrix-assisted laser-desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) analyses and showed that S. jiafu venom contains hundreds of peptides with a predominant mass of 3000-4500 Da. Patch clamp analyses indicated that the venom could inhibit voltage-gated Na+, K+ and Ca2+ channels in rat dorsal root ganglion (DRG) neurons. The venom exhibited inhibitory effects on tetrodotoxin-resistant (TTX-R) Na+ currents and T-type Ca2+ currents, suggesting the presence of antagonists to both channel types and providing a valuable tool for the investigation of these channels and for drug development. Intra-abdominal injection of the venom had severe toxic effects on cockroaches and caused death at higher concentrations. The LD50 was 84.24 μg/g of body weight in the cockroach. However, no visible symptoms or behavioral changes were detected after intraperitoneal injection of the venom into mice even at doses up to 10 mg/kg body weight. Our results provide a basis for further case-by-case investigations of peptide toxins from this venom.
Selenocosmia jiafu (S. jiafu) is recently identified as a new species of spider in P. R. China. These medium bodied venomous spiders are distributed mainly in the hilly areas of southwest of China, ...mostly at Yunnan and Guangxi Provinces. In order to understand the composition of the S. jiafu venom, we performed a preliminary analysis of this venom using reversed-phase high performance liquid chromatography (RP-HPLC), matrix-assisted laser-desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The S. jiafu venom was separated by RP-HPLC in an analytical C18 column (phenomenex 100 A, 250 mm x 4.6 mm, 5 µm) equilibrated with solution A (distilled water with 0.1% trifluoroacetic acid), using a gradient from 0% to 50% of solution B (acetonitrile with 0.1% trifluoroacetic acid) over 50 min with a flow rate of 1 mL/min. The isolated venom proteins were treated with in-gel digestion separated by SDS- PAGE and then identified by liquid chromatography-electrospray ionization quadrupole-time of flight mass spectrometry (LC-ESI-QTOF-MS) techniques. The results show that more than 40 fractions eluted were monitored at 215 nm in the RP-HPLC chromatogram of the venom of the spider S. jiafu. Most of the fractions were eluted with retention times of 5-15 min and 25-40 min, corresponding to 5%-15% and 25%-40% acetonitrile, respectively. The venom contains 238 peptides that follow a bimodal distribution, with about 62.5% of the peptides having a relative molecular mass of 3,000-4,500 and about 33.2% of the peptides having a relative molecular mass of 1,000-3,000. This distribution model is rather different from those of peptides from other tarantula spider venoms analyzed. To explore the relative molecular mass distribution of the venom proteins, the venom was analyzed by SDS-PAGE using standard protocols. Except for peptides with relative molecular mass lower than 10,000, the SDS-PAGE electrophoresis revealed three more obvious bands around 50, 72 and 90 kD respectively. Further MS analysis indicated that there are mainly hemocyanin, potassium ion channel protein, calcium protease and so on. Altogether, this study not only indicated there are many peptides and proteins in the S. jiafu venom, but also provided a basis for further case-by-case investigation of peptide toxins from this venom.
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